Kidney disease (CKD) tracking: hydration, appetite, and weight monitoring
This guide is general information and not a substitute for your veterinarian. Diet, medication, and fluid decisions for kidney disease are made with your vet.
Your cat or dog has been diagnosed with chronic kidney disease, and it's a lot to take in for a condition that often shows so little day to day. CKD is slow and steady, which is exactly why the small changes matter: a little weight loss, a bit more thirst, a meal left half-eaten. The daily job is noticing those and keeping a record, so you and your vet can respond early.
This page is the overview: what to track, when to call your vet, and how the record supports long-term care. Each part links to a fuller guide below. It's written with cats in mind, since CKD is so common in them, but it applies to dogs too.
What chronic kidney disease actually is
Healthy kidneys filter waste out of the blood, hold on to the water and protein the body needs, and help manage blood pressure and red blood cell production. In chronic kidney disease, working kidney tissue is gradually lost and doesn't grow back. What's left has to do more, and it does that partly by producing more dilute urine, which is why drinking and weeing more are often the first things owners notice.
The word that trips people up is chronic. It doesn't mean an emergency is underway. It means slow and ongoing. Many cats live comfortably for years after diagnosis, especially when it's caught early and managed steadily. That's the whole reason the small daily observations matter so much.
One hard fact worth knowing up front, because it explains why your vet reacts the way they do: by the time routine blood work shows a clear change, a substantial amount of kidney function has usually already been lost. It's not something you missed. It's how the disease is built, and it's why your vet cares about trends rather than any single result.
What the diagnosis is based on
Understanding the tests makes the results less frightening and the conversations easier to follow.
- Creatinine, a waste product healthy kidneys clear. It rises as function drops, but it's affected by muscle mass, so a very thin older cat can look better on paper than she is.
- SDMA, a newer blood marker that tends to rise earlier than creatinine and is less affected by muscle mass. It's often what catches CKD sooner.
- Urine concentration, which shows how well the kidneys are still holding on to water. A blood result means something quite different depending on what the urine shows, which is why your vet asks for both.
- Urine protein and blood pressure, which don't set the stage itself but refine it, and both are treatable in their own right.
Those results together produce an IRIS stage, a shared international shorthand for how far things have progressed. Our guide on CKD stages explained for owners walks through what each stage means in practice.
What treatment usually involves
There's no cure, and any site that suggests otherwise is one to close. What there is, and it's genuinely a lot, is slowing progression and keeping your pet comfortable. Your vet builds the plan, and it typically draws on a few things.
Diet does more heavy lifting than most owners expect. Therapeutic kidney diets are lower in phosphorus and adjusted in protein, and diet is one of the few interventions shown to extend good time in cats with CKD. The catch is that a diet only works if it gets eaten, and cats are opinionated about change. Switch slowly, and tell your vet rather than giving up quietly if it isn't going well.
Hydration matters because failing kidneys waste water. Wet food, extra water bowls, and fountains all help, and our hydration strategies guide covers the practical tricks. When drinking can't keep up, many owners learn to give subcutaneous fluids at home, which sounds far more daunting than it turns out to be.
Medication may address specific findings such as high blood pressure, protein in the urine, phosphorus levels, or nausea. Which ones apply depends on your pet's results, and that's a conversation for your vet rather than a checklist you can work from at home.
What to track
- Weight, weekly if you can, on the same scale. Slow loss is easy to miss without numbers.
- Water intake, roughly. The direction matters more than the exact amount. Our hydration strategies guide covers how to get more water in.
- Appetite, how keen your pet is and how much they finish.
- Urine, vomiting, and energy, the everyday signs of how your pet is doing.
- Medications and any fluids given, so the plan and the results line up.
Small, regular entries build a trend line that matters more than perfect daily notes. Weigh on the same day each week, note appetite before and after meals, and let the pattern do the work.
When to call your vet
CKD is managed over months, but some changes need a call rather than a note. Contact your vet if your pet stops eating, vomits repeatedly, becomes very flat or wobbly, or shows signs of dehydration like tacky gums, sunken eyes, or skin that's slow to spring back. A sudden drop in how your pet is doing, or a clear change in drinking or urinating, is also worth a call. When home care can't keep up with fluid loss, your vet may talk to you about subcutaneous fluids at home.
Why small changes matter
With a slow condition, the trend is the whole story, and the trend is built from your notes. A consistent record of weight, appetite, and thirst lets you and your vet see whether your pet is holding steady or drifting, long before a single test would show it. It also makes each recheck meaningful, because there's real data behind it, and it's what turns an IRIS staging result into something you can act on rather than just a number.
Bring consistent measurements and recent lab dates to each visit. "She's eaten half her food four days running and dropped a bit of weight" gives your vet far more than "I think she's a bit off."
Guides in this series
- Giving subcutaneous fluids at home
- Hydration strategies for CKD pets
- CKD stages (IRIS) explained for owners
Related guides
- Diabetes care for pets
- How much water should a cat drink?
- How much water should a dog drink?
- Seizure logging & epilepsy
Common questions
How often should I weigh my pet?
Weekly is a good rhythm for stable monitoring, more often if your vet asks. Use the same scale at a similar time of day, because slow weight loss is one of the earliest signs that something has shifted.
What do the IRIS stages mean?
They describe how far the disease has progressed, from Stage 1 (earliest, often no signs) to Stage 4 (most advanced), set from blood values plus urine protein and blood pressure. A stage guides treatment and isn't a countdown. The CKD stages guide explains each one.
How much should a CKD cat drink?
There's no single number, and a CKD cat often drinks more than a healthy one because the kidneys can't hold water back. Keep fresh water freely available and never restrict it. A sudden change in either direction is worth telling your vet.
Where this information comes from
This guide is written from living with a chronically ill pet and checked against published veterinary sources. It's general information, not advice for your individual animal. If you want to read further:
- Chronic Kidney Disease, Cornell Feline Health Center, Cornell University College of Veterinary Medicine. Covers diagnosis, IRIS staging, hydration, and subcutaneous fluids at home.
- IRIS Staging System, International Renal Interest Society. The staging system itself, published by the group that created it. Written for vets, but it's the primary source behind any stage you're given.
Felova is being built for exactly this, a calm place to track weight, hydration, and appetite so the trend is there when your vet needs it. It's not out yet. Until then, our printable logs do the same job on paper.
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